JP2001248113A - Steel and concrete composite slab - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To reduce the required anchoring length of a reinforcing bar in a steel-concrete composite slab and to omit on-site reinforcing bar work. SOLUTION: A bottom steel plate 1 constituting a bottom outer shell, vertical ribs 2 made of a plurality of strips arranged in parallel on a top surface side of the bottom steel plate 1 at predetermined intervals, and formed on the vertical ribs 2 at predetermined intervals. And a concrete 5 which is inserted into the hole 3 and is arranged in a direction perpendicular to the longitudinal ribs 2 and a concrete 5 which is cast on the bottom steel plate 1 and embeds the longitudinal ribs 2 and the muscles 10. A steel bar 11 in which fixing heads 12 are integrally formed at both ends is used as the distribution bars 10 in the composite steel-concrete slab.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel-concrete composite slab used, for example, as a slab of a steel bridge.

[0002]

2. Description of the Related Art FIG. 4 shows a well-known synthetic floor slab of this kind. This is the bottom steel plate 1 that constitutes the bottom shell.
A vertical rib 2 made of a plurality of strips arranged in parallel at a predetermined interval on the upper surface side of the bottom steel plate 1; and a vertical rib 2 inserted into a hole 3 formed at a predetermined interval in the vertical rib 2. It is composed of a power distribution bar 4 arranged in a direction perpendicular to the steel plate and a concrete 5 which is cast on the bottom steel plate 1 and embeds the vertical ribs 2 and the power distribution bar 4.

[0003] In this composite slab, when the concrete 5 is cast, the bottom steel plate 1 serves as a formwork, so not only the formwork and support work at the site can be omitted, but also after the concrete 5 is hardened. The bottom steel plate 1 and the concrete 5 are integrated through the ribs 2 and the distribution bars 4 to have excellent rigidity. In particular, the bottom steel plate 1 functions as a tensile member against a vertical load, and the vertical ribs 2 have a stiffening function for the bottom steel plate 1 and also function as a dowel for the concrete 5 when the concrete 5 enters the hole 3. The reinforcing bars 4 have a function of stiffening the vertical ribs 2 in the orthogonal direction and a function of preventing the concrete 5 from cracking.

[0004]

By the way, in the above-mentioned composite floor slab, ordinary deformed reinforcing bars or round steel bars are used as the distribution bars 4, but these distribution bars 4 are securely attached to the concrete 5. In order to fix it, one side of the vertical rib 2 is
A fixing length of about 0 times is required. In other words, when a deformed reinforcing bar with d = 16 mm is used as the distributing muscle 4, each distributing muscle 4
Is 40d = 640 mm on one side of the vertical ribs 2, so that a length extending over a plurality of the vertical ribs 2 is required.
In the case of round steel, it is necessary to further provide a 180-degree hook at the tip.

[0005] Since the distributing bars 4 having such a length are required, the above-described composite slab requires a large amount of reinforcing bars, which is disadvantageous not only in cost but also in such a long length. Since it is difficult to attach the reinforcing bars 4 to the longitudinal ribs 2 in advance, it is necessary to perform the reinforcing work again after the bottom steel plate 1 is installed, which is an obstacle to reducing the construction cost and the construction period. Therefore, effective improvement measures were requested.

[0006]

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention relates to a steel-concrete composite slab used as a slab of a steel bridge or the like, wherein a bottom bar steel constituting a bottom outer shell of the composite slab is provided. And a vertical rib made of a plurality of strips arranged in parallel at a predetermined interval on the upper surface side of the bottom steel plate, and inserted into a hole formed at a predetermined interval in the vertical rib and orthogonal to the vertical rib. And the concrete ribs which are cast on the bottom steel bar and bury the longitudinal ribs and the force bars. The anchoring heads are integrally formed at both ends as the force bars. It is made by using the bar steel.

[0007]

FIG. 1 shows a synthetic slab according to an embodiment of the present invention. The composite slab of this embodiment is shown in FIG.
Is an improvement of the force distribution bar 4 in the conventional composite floor slab shown in FIG. That is, as described above, the conventional composite slab uses ordinary deformed reinforcing bars or round bars as the distribution bars 4, and therefore, the distribution bars 4 are long to secure the anchoring length to the concrete 5. Although it is inevitable, the composite floor slab of the present embodiment can sufficiently save the required fixing length by using the steel bar 11 with the fixing head 12 as the distributing bar 10. ing.

[0008] Distributor 1 used in this embodiment
Numeral 0 indicates that the fixing heads 12 are integrally formed at both ends of a bar 11 such as a deformed reinforcing bar or a round bar as shown in FIG.
As the configuration of the fixing head 12, for example, the configuration shown in FIG. 3 is preferable.

FIG. 3A shows a tapered hole through which the steel bar 11 can be inserted at the center of the fixing plate 13 made of a square steel plate, and the end of the steel bar 11 is inserted into the hole. Then, the fixing plate 13 is fixed to the steel bar 11 in a fitted state by forming the fixing plate 13 into a taper shape, and this is used as the fixing head 12. The thickening of the bar 11 is performed, for example, by compressing the bar 11 in the axial direction in a state where the end of the bar 11 is made red by induction heating, thereby crushing the end of the bar 11 in the hole of the fixing plate 13. It can be easily and efficiently performed by swelling. The thickness of the fixing plate 13 serving as the fixing head 12 is preferably about 0.5 to 2 times the diameter d of the steel bar 11, and the length of one side is preferably about 2 to 5 times. FIG. 3 (b)
(A) except that the fixing plate 13 serving as the fixing head 12 is rectangular and the steel bar 11 is fixed at a slightly eccentric position.
Is similar to FIG. 3C shows an example in which the end portion of the steel bar 11 is thickened without using the fixing plate 13 as described above to form a frustoconical fixing head 12.

Since the above-mentioned steel bar 11 has the anchoring heads 12 integrally provided at both ends, the anchoring length with respect to concrete can be made sufficiently short. When used as the streak 10, its length is about 8d on one side of the longitudinal rib 2, that is, d = 16mm
In the case of, it is enough to be less than 130 mm, and the amount of reinforcing bar can be greatly reduced as compared with the case of using a conventional general mere deformed reinforcing bar, and it is also possible to attach this to the longitudinal rib 2 in advance. It is possible to omit the on-site rebar arrangement work, and even in the case of on-site rebar arrangement, it is easy to handle because it is short and lightweight, so that the workability can be greatly improved as compared with the related art. Moreover, the steel bar 11 with the anchoring head 12 can be easily manufactured by the method exemplified above, and if mass-produced to a certain standard, it can be manufactured at a lower cost than a rebar with hooks. From the above, by using this as the distributing bar 10, it is possible to greatly contribute to the reduction of the construction cost and the construction period when constructing the composite slab.

[0011]

The steel-concrete composite slab of the present invention
Since the steel bars with the anchoring heads integrally formed at both ends are used as the distribution bars, the length of the distribution bars required for anchoring to concrete is short, and the length of the distribution bars should be sufficiently short. As a result, it is possible to realize a reduction in the amount of rebar and omission of the on-site rebar arrangement work as compared with the conventional one, thereby reducing the construction cost and the construction period.

[Brief description of the drawings]

FIG. 1 is a view showing a synthetic slab according to an embodiment of the present invention.

FIG. 2 is a diagram showing a steel bar with a fixing head used as a distribution muscle.

FIG. 3 is a diagram showing a fixing head.

FIG. 4 is a view showing a conventional composite floor slab.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bottom steel plate 2 Longitudinal rib 3 Hole 5 Concrete 10 Distributing bar 11 Steel bar 12 Fixed head

Continued on the front page (72) Inventor Shuhei Okamoto 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Corporation F-term (reference) 2D059 AA17 2E162 AA01 BA02 BB07 CB02 DA02

Claims (1)

[Claims] 1. A steel / concrete composite slab used as a slab or the like of a steel bridge, wherein a bottom steel plate constituting a bottom shell of the composite slab and a top surface of the bottom steel plate are spaced apart from each other by a predetermined distance. A plurality of longitudinal ribs made of strip steel arranged side by side; a force-distributing bar inserted in a hole formed in the longitudinal rib at a predetermined interval and arranged in a direction perpendicular to the longitudinal rib; A steel which is cast on a steel plate and is made of concrete in which the longitudinal ribs and the distribution bars are embedded, and wherein the distribution bars are bar steels integrally formed with fixing heads at both ends.・
Concrete composite floor slab.